Why Google Maps Cordova ionic angular, only working in Android and blank in IOS?

**I'm submitting a ...** (check one with "x")
- [ ] question
- [ x] any problem or bug report
- [ ] feature request

**If you choose 'problem or bug report', please select OS:** (check one with "x")
- [ ] **Android**
- [ x] **iOS**
- [ ] **Browser**

**cordova information:** (run `$> ionic cordova plugin list`)

```
com-badrit-base64 0.2.0 "Base64"
com.googlemaps.ios 3.8.0 "Google Maps SDK for iOS"
cordova-android-play-services-gradle-release 4.0.0 "cordova-android-play-services-gradle-release"
cordova-androidx-build 1.0.3 "cordova-androidx-build"
cordova-plugin-androidx 2.0.0 "cordova-plugin-androidx"
cordova-plugin-background-geolocation 3.1.0 "CDVBackgroundGeolocation"
cordova-plugin-camera 4.1.0 "Camera"
cordova-plugin-datepicker 0.9.3 "DatePicker"
cordova-plugin-device 2.0.2 "Device"
cordova-plugin-document-viewer 0.9.13 "SitewaertsDocumentViewer"
cordova-plugin-fcm-with-dependecy-updated 6.3.1 "Cordova FCM Push Plugin"
cordova-plugin-file 6.0.2 "File"
cordova-plugin-file-transfer 1.7.1 "File Transfer"
cordova-plugin-filepath 1.5.8 "cordova-plugin-filepath"
cordova-plugin-geolocation 4.0.2 "Geolocation"
cordova-plugin-globalization 1.11.0 "Globalization"
cordova-plugin-googlemaps 2.8.0-20200601-1013 "cordova-plugin-googlemaps"
cordova-plugin-ionic-keyboard 2.2.0 "cordova-plugin-ionic-keyboard"
cordova-plugin-ionic-webview 5.0.0 "cordova-plugin-ionic-webview"
cordova-plugin-iroot 0.8.1 "iRoot"
cordova-plugin-nativegeocoder 3.4.0 "NativeGeocoder"
cordova-plugin-network-information 2.0.2 "Network Information"
cordova-plugin-screen-orientation 3.0.2 "Screen Orientation"
cordova-plugin-splashscreen 5.0.2 "Splashscreen"
cordova-plugin-statusbar 3.0.0-dev "StatusBar"
cordova-plugin-vibration 3.1.1 "Vibration"
cordova-plugin-whitelist 1.3.3 "Whitelist"
es6-promise-plugin 4.2.2 "Promise"
```

**package.json information:**
```
"@ionic-native/core": "^5.22.0-beta-1",
"@ionic-native/google-maps": "^5.5.0",
"cordova-plugin-googlemaps": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps.git#multiple_maps",
"cordova-plugin-googlemaps-sdk": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps-sdk.git",
```

**Current behavior:**
Google Maps is blank but it shows Google logo, Everything normal in Android.

I have added this line in config.xml :
````

````

Also, i've enable Google Maps for IOS and restrict with my bundle id (com.xxxxx.hris) as well.
Here the restrict information :
````
Maps SDK for iOS
Geocoding API
Geolocation API
Maps SDK for Android
Places API
Maps Static API
````

**Expected behavior:**
It should be running fine like Android

**Screen capture:**
[Android]

[iOS]

Start by reviewing the config.xml GOOGLE_MAPS_IOS_API_KEY preference and the package.json plugin versions, then run the listed ionic cordova plugin list command for the iOS setup. Verify the iOS API key and bundle-ID restrictions against the blank-map behavior. Done means the map renders on iOS rather than showing only the Google logo.

Written by the indexing model from the issue text.